PROJECT SUMMARY Hospital-based Animal-Assisted visitation programs provide an important complementary treatment in holistic patient care and reduce reduce patient stress, pain and anxiety. However, the risk of transmission of pathogens, such as methicillin-resistant Staphylococcus aureus, is a challenge to the sustainability of hospital- based Animal-Assisted visitation programs. Our pilot data suggest that a low-cost chlorhexidine-based intervention targeted to the dogs involved in the visitation programs holds high potential to reduce pathogen transmission during sessions. Therefore, we will enroll child participants who interact with 50 dogs over twelve sessions (six observational, six where the dog is randomized to intervention or control) at two enrollment centers. We will test the following aims: 1) To identify program-related risk factors for acquisition of hospital- associated pathogens by pediatric patients during AAI sessions during an initial run-in phase of no intervention; 2) To determine the effect of a chlorhexidine (CHX)-based intervention on acquisition of hospital-associated pathogens and microbial communities by patients during AAI sessions via a multicenter randomized controlled trial; and 3) To determine whether the specific benefits achieved by the visitation program, i.e. reduction in blood pressure, heart rate and self-reported pain and anxiety, are impacted by the intervention. If findings support the hypothesis that this intervention is effective to reduce pathogen transmission through a multicenter, parallel-arm randomized controlled trial and does not reduce Animal-Assisted visitation program benefits to the children or impact the welfare of the therapy dogs, then we will have strong evidence on which to base recommendations for infection control guidelines for programs nationally.!